The invention relates to a sample feeder for use in an automatic electrophoresis system, and more particularly, to a feeder which is adapted to feed a plurality of samples to be examined into alignment with the sample applicator of an electrophoresis system.
As is well recognized, an automatic electrophoresis system may be used to examine the protein of blood serum in hospitals, for example. A sample bearing member in the form of a sheet of a material such as cellulose acetate is dampened with a buffering solution by means of a dampening roller before it is brought to a sample application position where blood serum, as a sample to be examined, is applied to it. The member with serum applied to it is then fed into an electrophoretic vessel which is then electrically energized to effect an electrophoretic process, which produces a fractionated pattern. Subsequently, the member is moved into a dyeing vessel where it is dyed, followed by decoloration and drying steps. Finally, the serum is examined photometrically by means of a densitometer, output data from which are recorded.
The serum is applied to the sample bearing member by means of an applicator as shown at 1 in FIG. 1. Specifically, the applicator 1 includes a plurality of application members 2 which are carried by a holding arm 3 at a regular spacing. Each application member 2 comprises a plate-shaped penpoint 4 having a surface 4a on its free end on which blood serum is deposited and which is fixed to the free end of a support shank 5. The shank 5 fixedly carries a laterally extending pin 6 which is engaged with an elongate slot 3a formed in the holding arm 3, thus allowing a limited vertical movement of the shank relative to the arm.
When blood serum is to be deposited on the bearing members by using the applicator 1, holding arm 3 is located over and moved down toward a sample container 7 having a plurality of dish-shaped recesses 7a each containing a different blood serum. The serum sample is deposited on the surface 4a of the penpoint 4. As illustrated in FIG. 2, the container 7 comprises an elongated, plate-shaped member having a plurality of dish-shaped recesses 7a formed in a row in its upper surface, regularly spaced and corresponding to the adjacent penpoints 4 of the applicator 1. After the penpoints 4 are immersed in the recesses 7a to allow blood serum to be deposited on the individual penpoints 4, the holding arm 3 is moved upward and is then moved over sample bearing members (not shown). The applicator is then moved down to cause individual penpoints 4 to abut corresponding bearing members, thus applying the blood serum samples to the latter.
An automatic electrophoresis system is capable of applying a number of blood serums to different bearing members automatically at one time. In addition, it automatically effects the fractionation, dyeing, decoloration and colorimetric quantitative determination for a plurality of serums in succession.
However, it will be noted that a plurality of sample containers 7 each containing samples to be tested must be initially prepared and then placed one by one, in the proper position relative to the applicator 1 in order that all the samples in all the containers 7 can be tested. In the prior art practice, this operation was performed manually. While other processing steps occur automatically in an automatic electrophoresis system, manual supply of samples by an operator results in reduced overall efficiency. Additionally, the manual operation is cumbersome. Thus, it will be apparent that there has been a need for automatic supply of samples.